Lawn mower sharpener



y 1943- E. TOEPFER L AWN MOWER SHARPENER Filed Aug. 9, 1-945 2 Sheets-Sheet l INVENTOR EDWARD J. TOEPFER ATTORNEYS May 4, 1948. E. J. TOEPFER LAWN MOWER SHARPENER Filed Aug. 9, 1945 2 Shets-Sheet 2 IIIIIIIIIIIII INVENTR EDWARD J.TOEPFER Z L AT ORNEYS Patented May 4, 1948 UNITED STATES PATENT OFFICE LAWN'MOWER SHARPENER Edward J Toepfer, Milwaukee, Wis.

Application August 9, 1945, SerialNo. 609,848

2 Giaims. 1

My invention has for its primary object to provide a simple, economical and effective grinding machine for lawn mowers or the like, the construction and arrangement being such that an operator unskilled in the art may sharpen a mower, having the highest grade finish, without previous knowledge in the trade. Another object of my invention is to provide a lawn mower sharpening machine, the units of which can readily be dismounted, with relation to each other, and nested in a compact area, whereby the mechanism can be transportedirom place to place, for the purpose of obtaining sharpening orders, at their various locations of use, it being noted that the knock-down and assemblage operation of the various parts is accomplished without manipulation of bolts or other locking assemblage means.

Another and important object of my invention is to provide a carriage upon which is mounted a motor driven extended shaft carrying a grinder wheel, the same being balanced with relation to the carriage rollers, whereby the grinder may be readily manipulated for engagement with the spiral knives of a lawn mower, the carriage bemg adapted to travel back and forth to. permit the grinder wheel to perform a sharpening. operation upon each spiral knife. A still further object of my invention is to provide the overhung balanced motor driven shaft and grinder wheelsupported upon atable and associated with a detachable bed, with ad- .iu'stable supports for a lawn mower, whereby the blades thereof are correctly positioned for a sharpening operation and the mower supports are capable of manipulating the mower for oiling or other repair work that may be necessary. With the above and other objects in view, which will appear as the description proceeds, the invention resides in the novel construction; combination and arrangement of parts, substantially as hereinafter described, and more particularly defined by the appendedclaims, it being understood that such changes in the precise embodiment of the herein disclosed invention may be made as come within the scope of the claims. In the accompanying drawings is illustrated one complete example of the physical embodi ment of the present invention constructed ac"- cording' to the best mode so" far devised for the practical application of the principles thereof.

In the drawings: g V Figure 1 represents a side elevation of a-grlnder machine embodying the features of my invention and illustrating, in dotted lines; a lawn and 2, particularly illustrating an inverted mower,

in full lines, fitted to "its bed supports for a sharpening operation. b

Figure 4 is a detailed longitudinal sectional view of the grinder wheel and associated parts, the section" being indicated by line 4-4 of Figures 1 and 3. And

Figure 5 is a cross sectional view through the motor carriage and associated parts, the section being indicated by line 5-5 of Figure 1.

Referring by characters to the drawings, A indicates a table, which may be mounted upon any suitable bed B, as indicated in Figure 1. The bed has secured to its ends upstanding companion brackets i--l, which brackets, at their upper ends, have secured thereto a pair of tubular rails 32 in parallel relations. The brackets and rails are suitably braced from end to end by cross strips 3'--3- connected at their centers and secured by screws to the brackets at their ends.

The rails are supplied for the support of a reciprocative carriage frame 4, the front end of which has upwardly extending therefrom an arm 5 terminating with a split collar 5 for c1amping engagement with the breech end of a sleeve 6.

The carriage frame carries ayoke l, fixedly secured to said carriage by a pair of clips 8 and set bolts. 'ihe yoke terminates with upwardly extended legs 9, for the reception of track rollers Hlifi, it being noted that the track rollers are positioned just rearwardly of the carriage 5, whereby said carriage may be reciprocated, back and forth. upon the rails and also vertically oscillated'with reference thereto.

Due to the arrangement of the carriage wheels and hanger yoke, it is apparent that said wheels may be adjusted slightly hack and forth to insure a perfect balance between the sleeve and motor.

As noted in Figure l of the drawings, when the carriage is in its rearward position, the sleeve, which is rigidly mounted in the carriage arm, terminates at a point slightly beyond the front rail bracket i. Rigidly secured to the carriage bottom plate is an electric motor C, having its shaft H extendingthrough and journaled in the sleeve- 6. The end of the motor shaft projects beyond the sleeve and has secured thereto 'a-n blades D. A further guide for controlling the grinder wheel, comprises an adjustable rod l5, which rod terminates with a down-turned toothed end I5 for engagement with the edge of the shear blade E of the mower.

The opposite end of the rod I5 is adjustably mounted in a head casting l6, which casting is pivotally connected to an ear [3' of the housing l3. The toothed end rod I5 is adjustable in the head casting l6 by a spindle ll mounted in a barrel portion of the housing and. in threaded engagement with the end of said rod. The adjustment of the fingered end rod is for the purpose of regulating the grinder wheel contact with the blades, when said wheel may be reduced in circumference due to wear.

The handle I6 extends from the head casting 1B for the purpose of manipulating a grinding operation, whereby the grinding wheel, and associated parts, may be lifted and manually moved back and forth relative to the partially spiral mower knives.

While I have shown and specifically described manually controlled means for manipulating the grinder wheel, whereby it ismoved'back and forth and accurately guided in this movement, it is understood that I may vary the features of such mechanism without departing from the spirit of my invention, and substitute mechanism may be employed for the above mentioned purpose, within the knowledge of the skilled mechanic.

Referring now especially to means for adjustably supporting all standard types of lawn mowers, preparatory to the same being associated with my sharpening mechanism, I, preferably, provide a movable pad F, which is mounted forwardly of the rail frame upon the bed B. The pad has an upwardly extended standard [8, upon which is a vertically adjustable clamp-rod l9, and above the same is a vertically adjustable, guide roller rest pin l9. Upon opposite sides of the standard I8 is a pair of stirrup rods adjustably secured to socketed posts 20', which posts are secured to the pad F, as best indicated in Figures 1 and 3 of the drawings.

As best indicated in Figures 2 and 3 of the drawings, the support for the mower also includes a stirrup ended stem 2|, which stem is adjustable in a socketed post 2!, and the post may be positioned in any desired manner upon the pad F, for serving as a support, for the shear blade ground roller G of a mower, as clearly indicated in Figure 3.

From the foregoing description, when it is desired to sharpen the blades D of a standard mower, in practice, the handle is first removed from the mower and it is turned upside down and seated in the stirrup upside down with its guide roller G nested within the stirrup stem '2l. The said mower is then fixedly anchoredby its frame rod H, which is seated in the stirrup rod 2l-. This frame rod-H is furthermore locked in' its seat by the clamping-rod l 9, as shown in Figure 3.

Hence, when thev moweris so positioned it'can e be approximately aligned with the sharpening wheel or, as indicated in dotted lines of Figure 3, it may be rocked backwardly and upwardly to the position shown, whereby it is supported about its pivot point by the pin l9, which pin will engage the mower guide roller. In this dotted position suitable inspection and repairs may be efiected and also the mower may be properly oiled. In other words, the mower is not only sharpened, but" it is also adjusted and tuned .up to perform its cutting functions properly.

When the machine is in the position indicated in Figure 1, a sharpening stroke of the abrasive wheelhas just been completed. To perform another stroke upon the blade of the mower, as is indicated in dotted lines, the operator tilts the counter-balanced carriage upwardly upon the rollers Ill. This movement is efiected by,

manually swinging the grinder means by the handle Hi. The operator then draws the grinder wheel forward and the carriage rides uponthe rails 2. The grinder wheel is then tilted downwardly and engages a lawn mower blade at its forward end, and at the same time the tooth of the guide rod will engage the shear blade E of said mower. Y

In the above position the grinder mechanism is slowly moved backward, to repeata sharpening operationof; the blade, which bladewill automatically-slowly rotate to conform to its spiral twist, and the beveled cutting edge of said blade is ground by exerting downward pressure upon the handle toeffect the cut. Thus the; operation is repeated until all the blades are properly sharpened at the correct bevel, which bevel is determined by the adjustments of the finger l4 and guide tooth riding the edge of the shear blade. 3 a

While the sharpening machine hasbe'en particularly developed for grinding blades of lawn mowers, obviously it is capable of grinding the knives of various machines and, as forexample, skates may be fitted to the supporting pad -B for simple grinding. I I claim: '1. A grinding machinefor lawn mowers or the like, comprising a table, a frame extendingfrom the table, rails carried'thereby, acarriage mounted between the rails; wheels journaled upon the carriage engaging said rails, an arm; extended upwardly from the front of the carriage, a sleeve secured to the arm andextending forwardly therefrom,. a motor mounted upon the carriage rearwardly of the wheels, a motor driven shaft journaled-in the sleeve and extending beyond the same, a grinder wheel secured to the extended end of said shaft, a housing partly encasing the grinder wheel extending from the sleeve, an adjustable guide means carried by the-housing adapted to engage the shear-blade and knife blade of alawn mower, and means for supporting;a lawn mower beyond the rails and-in ap. proximate alignment with the aforesaid "grinder Wheelh v 2. A grinding machine for lawn mowers or the like comprising a carriage,- an :arm extendingupwardly therefrom, a motor mounted upon the carriage rearwardly ofsthe arm,=,a table, rails carried-thereby, an overhanging sleev secuied to the: carriage arm, a motordriven shaft journaled in-theysleeye, a. yoke pivoted-to the carriage, a grinder wheel secured to theoutenend oft-he shaft, ancla pair of supporting; wheels mounted upon the-yoke engageable with the rails the same .bein-g ,posi-tionedbetween the motor and sleeve,

whereby the grinder wheel may be moved back UNITED STATES PATENTS and forth upon the track and raised or lowered upon the carriage wheels, the said grinder wheel Number Name Date and overhung sleeve being counter balanced upon 1,271,837 B1118 July 9, 1918 the carriage wheels by the weight of the motor 5 1,605,890 Brown Nov. 2, 1926 positioned rearwardly of said carriage wheels. 44,5 Venable June 3, 1941 EDWARD J. TOEPFER. 2,279,793 shelbume Apr. 14, 1942 2,281,055 Smith Apr. 28, 1942 REFERENCES CITED 2,377,126 Brown May 29, 1945 The following references are of record in the file of this patent: 

